Folding stairs



C. R. BROPHY FOLDING STAIRS Nov. 8, 1966 Filed Feb. 18, 1965 C A RL R. BROPH Y BUCKHOR/V, BLORE, KLA/POU/ST 8 SPARK/LIAM ATTORNEYS United States Patent 3,283,853 FOLDING STAIRS Carl R. Brophy, P.0. Box 122, Clackamas, Oreg. Filed Feb. 18, 1965, Ser. No. 433,704 Claims. (Cl. 182152) This invention relates to a folding stairs, and more particularly to a folding stairs having an improved latch structure.

An object of the invention is to provide a new and improved folding stairs.

Another object of the invention is to provide a folding stairs having a new and improved latch structure.

A further object of the invention is to provide a folding stairs having a pair of rigidly bracing, quick-releasable latches.

Yet another object of the invention is to provide a folding stairs having latching braces which are biased into latching engagement with legs and supporting straps thereof and form rigid bracing triangles with the legs, straps and treads of the stairs.

The invention provides a folding stairs in which treads are pivotally connected to straps and rear legs at the rear edges of the treads. The treads also are pivotally connected to front legs at the forward edges of the treads to form parallelogram linkages with the straps and the front legs. Latching braces pivoted at the upper ends thereof to the forward portions of the ends of the top tread are provided with inwardly directed pins which enter holes in the straps from the outer faces of the straps to form triangles with the top tread and the straps. The latching braces also are provided with outwardly directed pins at the lower ends thereof adapted to enter holes in the rear legs from the inner faces of the straps to form rigid bracing triangles with the rear legs, the top tread and the straps. Each latching brace is positioned on opposite sides of the straps and the rear legs so that the straps normally hold the braces against the rear legs and the rear legs normally hold the braces against the straps. The straps and the braces are sufficiently rigid to rigidly brace the stairs but are sufficiently flexible to permit the straps to be first moved so as to move the pins out of the holes in the rear legs and then be moved so as to withdraw the pins from the straps, and also permit easy manipulation of the braces into latching engagement.

A complete understanding of the invention may be 0-btained from the following detailed description of a folding stairs forming a specific embodiment thereof, when read in conjunction with the appended drawings, in which:

FIG. 1 is a perspective view of a folding stairs forming one embodiment of the invention;

FIG. 2 is a generally vertical section, taken along line 2-2 of FIG. 1; and

FIG 3 is a side elevation view of the folding stairs of FIG. 1 While in its folded, storage condition.

Referring now in detail to the drawings, there is shown therein a folding stairs which includes two iron angle rear posts or legs rigidly secured together by braces 11 and pivotally secured to the opposite ends of a top tread 12 by bolts 14 near the rear edges of the top tread. The rear legs 10 are provided with enlarged feet 15. The bolts 14 also secure a pair of links or straps 16 to the top tread. The straps 16 are pivotally secured by bolts 18 to the ends of a bottom tread 20 near the rear edges thereof. The straps 16 form parallelogram linkages with the treads 12 and 20 and strap-like front legs 24, which are secured pivotally to the ends of the tread 12 near the forward edge thereof by bolts 26. The front legs 24 are secured pivotally to the ends of the tread 20 near the forward edge of the tread 20 by bolts 28. The legs 24 are provided with feet 29 at the bottoms thereof.

A pair of strap-like, latching braces 30 are pivotally secured to the ends of the top tread 12 by the bolts 26. The braces 30 have inner pins 32 projecting inwardly from the adjacent inner faces of the central portions thereof. The pins 32 are located equidistantly from the bolts 26. The braces also have outer pins 34 projecting outwardly from the outer faces of the lower end portions thereof. The free ends of the pins 32 and 34 are slightly rounded, and holes 36 in the straps 16 are slightly larger than the pins 32 for receiving the pins 32 easily. The pins 34 are adapted to enter holes 38 in the side flanges of the rear legs 10 to latch the braces 30 thereto, and form rigid triangular bracings with the legs 10, the tread 12 and the straps 16. The straps 16 are rather stiff, and the braces 30 also are rather stiff and are sufficiently strong to form rigid braces. However, the braces and straps are sufficiently resilient to permit quick insertion of the pins 32 and 34 in the holes 36 and 38, respectively.

The folding stairs is shown in FIG. 1 in its rigid, operative condition, and may be folded to compact storage position, as illustrated in FIG. 3. When the stairs is in its rigid, operative position the latching braces 30 extend across the outside faces of the links 16 and the lower ends of the braces 30 overlaps the inside faces of the: side flanges of the rear legs 10 so that the braces 30 are latched or trapped in the latching positions. To release the stairs for folding, the lower end of each brace 30 is pressed in wardly to withdraw the pins 34 from the holes 38, the legs 10 are moved out away from the legs 24, and then each brace 30 is moved outwardly to withdraw its pin 32 from the hole 36. The stairs then is easily folded to the position shown in FIG. 3 in which the treads lie in closely adjacent parallel planes, the front legs lie along the rear legs, and the braces 30' lie along the legs.

The above-described stairs are shown with two treads 12 and 20, but may, of course, be provided with treads (not shown) pivotally secured to the straps 16 and the front legs 24 between the top and bottom treads,- with the legs and the straps 16 proportionately longer to accommodate the extra treads. The above-described stairs fold to a very thin, compact storage condition and also, when the stairs is in its operative position, it is very rigidly braced. I

It is to be understood that the above-described arrangements are simply illustrative of the application of the principles of the invention. Numerous other arrangements may be readily devised by those skilled in the art which will embody the principles of the invention and fall within the spirit and scope thereof.

What is claimed is:

1. In a folding stairs,

a top tread,

a bottom tread,

a pair of rear legs having connecting portions intermediate the ends thereof and pivotally connected to the portions of the ends of the top tread adjacent the rear edges of the top tread,

a pair of front legs pivotally connected to the portions of the ends of the treads adjacent the .front edges thereof,

a pair of braces each pivotally connected at one end to one of the portions of the ends of the top tread adjacent the front edge of the top tread,

strap means connecting portions of the bottom tread adjacent the rear edge thereof to the rear legs for pivotal movement relative thereto,

quick detachable means connecting the other end of each brace to one of the connecting portions,

and quick-detachable means for connecting the central portions of the braces to the central portions of the strap means. 7

2. In a folding stairs,

a top tread,

a bottom tread,

a pair of rear legs having connecting portions intermediate the ends thereof and pivotally connected to the portions of the end of the top tread adjacent the rear edge thereof,

7 a pair of front legs pivotally connected to the portions of the ends of the top tread adjacent the front edge thereof,

a pair of braces each pivotally connected at one end to the portions of the ends of the top tread adjacent the front edge thereof,

a pair of straps pivotally connected to said portions of the end of the top tread adjacent the rear edge thereof and pivotally connected to the end of the bottom tread adjacent the rear edge thereof,

quick-detachable means connecting the other end of each brace to one of the connecting portions,

and quick-detachable means connecting the central portion of each brace to the central portion of each strap.

3. In a portable folding stairs,

a top tread, i

a bottom tread,

a pair of rear legs pivoted at the top thereof to the top tread and having holes in the central portions thereof,

a pair of front legs pivoted at the top thereof to the top tread and pivoted at the central portion thereof to the bottom tread,

a pair of supporting straps pivoted on a predetermined axis to the rear legs and the top tread and also pivoted to the bottom tread,

a pair of latching braces pivotally mounted at the upper ends thereof to the ends of the top tread and extending over the outside faces of the supporting straps and the inside faces of the rear legs,

a pair of inwardly directed latching means carried by the braces adapted to detachably engage the supporting straps,

and a pair of outwardly directed latching means carried by the braces adapted to detachably engage the rear legs, the latching braces having suflicient resiliency for the braces to be flexed outwardly sufliciently to permit the inwardly directed latching means to be moved to and from latching engagement with the straps and for the braces'to be flexed inwardly sufficiently to permit the outwardly directed latching means to be moved to and from latching engagement with the rear legs.

4. In a portable folding stairs,

a pair of rear legs having top holes at the top end portions thereof and also having lower holes in the central portions thereof,

a pair of front legs having top holes at the top end portions thereof and also having central holes in the central portions thereof spaced a predetermined distance from the top holes,

a pair of supporting members having top holes in the top end portions thereof, bottom holes spaced said predetermined distance from the top holes thereof and central holes between the top and bottom holes thereof,

a top tread having rearwardly positioned holes in the ends thereof and also having forwardly positioned holes in the ends thereof,

a bottom tread having rearwardly positioned holes in the ends thereof and also having forwardly positioned holes in the ends thereof,

a first pair of bolt means extending through the top holes of the rear legs, the top holes of the members and the rearwardly positioned holes of the top tread to secure the rear legs, the members and the top tread pivotally together,

a second pair of bolt means extending through the bottom holes of the members and the rearwardly positioned holes of the bottom tread to secure the members pivotally to the bottom tread,

a third pair of bolt means extending through the central holes of the front legs and the forwardly positioned holes of the bottom tread to secure the front legs and the bottom tread pivotally together,

a fourth pair of bolt means extending through the top holes of the front legs and the forwardly positioned holes of the top tread to secure the front legs and the top tread pivotally together,

and a pair of latching braces pivotally mounted at the upper ends thereof to the fourth pair of bolt means and having a pair of inwardly directed central pins adapted to enter the central holes of the members and a pair of outwardly directed lower pins adapted to enter the central holes of the rear legs,

the latching braces having suflicient resiliency for the braces to be flexed outwardly sufliciently to permit the central pins to be moved to alignment with the central holes in the members and the braces to be flexed inwardly sufliciently to permit the lower pins to be moved to alignment with the central holes in the rear legs.

5. In a portable folding stairs,

a pair of rear legs having top holes at the top end portions thereof and also having lower holes in the central portions thereof,

means connecting the rear legs together and bracing the rear legs,

a pair of front legs having top holes at the top end portions thereof and also having central holes in the central portions thereof spaced a predetermined distance from the top holes,

a pair of supporting straps having top holes in the top end portions thereof, bottom holes spaced said predetermined distance from the top holes thereof and central holes positioned between the top and bottom holes thereof,

a top tread having rearwardly positioned holes in the ends thereof and also having forwardly positioned holes in the ends thereof,

a bottom tread having rearwardly positioned holes in the ends thereof and also having forwardly positioned holes in the ends thereof,

a first pair of bolt means extending through the top holes of the rear legs, the top holes of the straps and the rearwardly positioned holes of the top tread in the order named to secure the rear legs, the straps and the top tread pivotally together,

a second pair of bolt means extending through the bottom holes of the straps and the rearwardly positioned holes of the bottom tread to secure the straps pivotally to the bottom tread,

a third pair of bolt means extending through the central holes of the front legs and the forwardly positioned holes of the bottom tread to secure the front legs and the bottom tread pivotally together,

a fourth pair of bolt means extending through the top holes of the front legs and the forwardly positioned holes of the top tread to secure the front legs and the top tread pivotally together,

and a pair of latching braces pivotally mounted at the upper ends thereof to the fourth pair of bolt means and having a pair of inwardly directed central pins adapted to enter the central holes of the straps and a pair of outwardly directed lower pins adapted to enter the central holes of the rear legs,

the latching braces having suflicient resiliency for the braces to be flexed outwardly sufficiently to permit the central pins to be moved to alignment with the central holes in the straps and the braces to be flexed inwardly sufliciently to permit the lower pins to be 5 6 moved to alignment with the central holes in the rear FOREIGN PATENTS legs- 646,245 7/1928 France.

References Cited by the Examiner REINALDO P. MACHADO, Primary Examiner.

UNITED STATES PATENTS 5 705,475 7/1902 John 182161 1,630,747 5/1927 Johnson 182-33 2,952,301 9/1960 Schlaak 182-156 

1. IN A FOLDING STAIRS, A TOP TREAD, A BOTTOM TREAD, A PAIR OF REAR LEGS HAVING CONNECTING PORTIONS INTERMEDIATE THE ENDS THEREOF AND PIVOTALLY CONNECTED TO THE PORTIONS OF THE ENDS OF THE TOP TREAD ADJACENT THE REAR EDGES OF THE TOP TREAD, A PAIR OF FRONT LEGS PIVOTALLY CONNECTED TO THE PORTIONS OF THE ENDS OF THE TREADS ADJACENT THE FRONT EDGES THEREOF, A PAIR OF BRACES EACH PIVOTALLY CONNECTED AT ONE END TO ONE OF THE PORTIONS OF THE ENDS OF THE TOP TREAD ADJACENT THE FRONT EDGE OF THE TOP TREAD, STRAP MEANS CONNECTING PORTIONS OF THE BOTTOM TREAD ADJACENT THE REAR EDGE THEREOF TO THE REAR LEGS FOR PIVOTAL MOVEMENT RELATIVE THERETO, QUICK-DETACHABLE MEANS CONNECTING THE OTHER END OF EACH BRACE TO ONE OF THE CONNECTING PORTIONS, AND QUICK-DETACHABLE MEANS FOR CONNECTING THE CENTRAL PORTIONS OF THE BRACES TO THE CETRAL PORTIONS OF THE STRAP MEANS. 